Time-element circuit-breaker.



i -[A EEN- I TIME ELEMENT CIRCUIT BREAKER. APPLIGATiQN mum P B.1,' 1911.

' Patented June .18, 1912 UNITED STATES PATENT OFFICE HALFDAN A. sum

,oF MILWAUKEE, WISCONSIN, ASSIGNOR T ALLIS-CHALMERS COMPANY, A CORPORATION OF NEW JERSEY.

- 'rmnsnnmvinnr OIRCUITTBREAKER Specification of Letters Patent; 4 Patented June 118, 1912 Application filediebru'ary 1, 1911. Serial No. 605,869.

Element Circuit-Breakers, of which the fol 'lowing is-a full', clear, and exactspecification.

My invention relates to time elementcir-.

cuitbreakers. I v 'It s'often desirable that acircuit-breaker permit an oi 'erload on-an electric circuit to continue for tnne'before causing the interruption of. the circuit, as generally electrical apparatus will stand overloads which are not of 'too long duration. Various circuit-breakers have been devised for accomplishing this. Sometimes they have been arranged so that they cause the interruption of thecircuit'inore quickly on heavy overloads than-on light overloadsv Myfl present invention is an improvementon There is a coil responsive to the current or other condition inthe circuit, and thiscoil, upon the occurrence of an overload orother abnormal condition-,causes the energization' of an electron' iagnet, which,wh'en energized fora-predetermined time, pr0duces a suiticient movement of certain movable parts to cause the tripping of a circuit-breaker.,' The time element required for the movement produced by-this inagnetis obtained by any suitable retarding device, such as .a dashpot, and the parts moved by the electromagnet may-act directly or indirectly to cause the tripping of the circuit-breaker. In the preferred form of my invention the elect-roinagn et operates a switch which controls the circuit of another 'elctromagnet, the latter controlling the tripping of the circuit-breaker; An auxiliary electromag s netlc device may be provlded. this device under certain conditions assisting the electromagnct acting on said switch.

The various novel features 01' my invention will appear from the description and drawings, and will be particularly pointed out inthc, claims.

The two figures'of the drawing show diagrammatically two embodiments of m ninvention, as opcralcdon closed circuit and open circuit rcspcctively.

In the arrangement shown in Figure l a three pole circuit-breaker is arranged in the mains 11 oi a three phase or a three Wire system, and, though biased to open position, may be held in closed position by a 'novoltage' coil 12 acting on a latch 13.

Coils 14, responsive to the current in the system as bybeing arranged in the'niains ll or some of them, when energized by an overload on the system raise the switch 15 into engagement with the contacts 16 and This closes the circuit-of the coil 18 across two mains of the circuit 11, or any other source of reasonably constant voltage, and the coil 18 lifts its core 19, the latter being retarded by the dash-pot 20. It the overload continues and in" consequence the switch 15 remains closed sufiiciently long,

a collar 21 on an extension of the core 19 engages the normally closed switch 22 and raises it from its cooperating contacts, thus breaking the circuit of the lie-voltage coil 12and allowing the spring 23 to release the latch 13 to trip the circuit-breaker 10. The length of time reqi'iired may be' adjustable in any desired manner, as by a rheostat 18.

In case the overload exceeds a predetermined-amount, the coils 14 are energized sufli'ciently to bend the springs 2% upon which the contacts 16 and 17 are mounted and bring the latter into engagcn icnt with the auxiliaryrontact's 25 and 26. This completes'the circuit for the auxiliarv solenoid 27, which, when energized, assists the solenoid 18 to raise the core 19. The energization of solenoid 2T diminishes the time required for opening the, switch and causing the tripping oft-he circuit-breaker it). The amount of such'diminution may be ad justed,-as by a rheostat 27 In: the arrangement shown in 62, there is a two p'ole circuit-'ln'ealrer 30 in the mains 31-of a direct current or a single] phase alternating current circuit. lhe circuit-breaker 80 is biased to open position,

but when closed is locked closed by means of the latch 32. Upon an overload in the mains 3l,'the coil 33, connected so as to be responsive to the current in such mains, closes the switch 3-]: and energizes the solenoid 35 by connecting it, across the mains 31 or any other suitable constant voltage circuit. The solenoid 85, when energized, begins to raiseits core 36 and the normally open switch 3T carried therehy, the moretar-ding 1 means.

- in comhmatn-ui, an eiectric circuit, a circuit-breaker therein, a coilresponsn'c to Brent of the .ccr'e and switch being retarded i l bythedaslrpot Sb. It the overload on tin inams 31 oontnmes long enough, the solc noid' 35'ti11'all31-closes the switch 3?,ihus

completing the circuit of the tripping coil 39, which, acting on. the latch itto open.

moves it .to'release the eircui.tln:eaker 30 and allows "Many lllot rangein'ent shown, an .lv described may he made without departing from the spirit and scopeof my inventiom and all such I aim to eorer' inthe folio mg claims.-

i l-"hatI claini as new i-st' V I e I 1. In combination, an electric circuit, a circuit-breaker in said circuit, a coil respon: site to electrical conditions therein, 1 a switch which is closed upon suilicient energii'ation of said coil, a pair. of eonsecutireliv acting c'oils adapted to he energized upon the complete closing of said switch, a see-- ondswiteh which is operated by said last mentioned coils, means :tor retarding the operation of-said second switch, and a third Icoil controlled by said switch and controllingtl'iei tripping of said circuit-breaker.

2. In combination, an electric eircuit,-a circuit-breaker therein, a coil! responsive to the current .in said circuit, a switch which is closed by said coil upon sufiicient energization thereof, a pair of consecutively acting coilsadapted to be energized upon the complete closing of said switch, means operated [by said 'lastflinentioned coils. and

controlling the tripping of said circuit-' breaker, and a time-element device tor reations in the precise ar' the operation of said last-named the'curre'nt in said-circuit, switching apparatus operated. by said coil, two coils which cooperate. when both are energized and which are energized by said switching mechanism when the current in said circuit reaches two predetermined Values respecwhich operated by said two cooperating coils or either of them when energized,

aneans for retarding the operation of said switch, and an electroinagnet the c1rcuit of which is controlled by said switch and which eontrolsthe tripping of said circuitbreaker.

Milwaukee, Wis, Jan. j), 1911.

In testimony whereof I afiix my signa' .ture, in the presence of two-witnesses.

HA-LFDAN A, STEEN. ll'itnesses CHAS. L. Brno), Ron. E.-S'roLL., 

